Armed mount for aircraft



Feb. 20, 1951 E. w. STACEY ETAL 2,542,217

ARMED MOUNT FOR AIRCRAFT Filed Nov. 1,1946 15 Sheets-Sheet 1 Inv enforsErnes z WSzacey Daniel LWzZ/rerhan n able George Kji z'cha rdson A rzfhurZE. Hu bbara their Agra/"nay Feb. 20, 1951 E. w. STACEY ET AL2,542,221 7 ARMED MOQNT FOR AIRCRAFT Filed Nov. 1, 1946 15 Sheets-Sheet2 63 126 76 '2'), I v o 5- 00 012,?! o 116 134 0O 0 O l 66 JuverziorsErnest WSzcwey Dan 2e! l Vllrerhhnnable George [11' fl?! chard sonArZhu/"RHubbard B zlzez'rAtzorneg Feb. 20, 1951 Filed Nov. 1, 1946 E- W.STACEY ETAL ARMED MOUNT FOR AIRCRAFT Emil- 15 Sheets-Sheet 3 :3Ynventors Ernest WS'zacey Daniel l/Valkerflannable George K EichardsonAr'zh urEfHubbard E. W. STACEY ETAL ARMED MOUNT FOR AIRCRAFT Feb. 20,1951 15 Sheets-Sheet 4 Filed Nov. 1, 1946 Inventors Em es 2 WSzczcegeK/Ezc/z ardsorz bbar'd lllHHlHll II!!! II llllllil llll B their At orneDaniel T/VaZ/cerHcmnabZe Georg Arth urEHu Feb. 20, 1951 E. w. STACEYETAL 2,542,217

ARMED MOUNT FOR AIRCRAFT Filed Nov. 1, 1946 15 Sheets-Sheet 5 we]; v O O43 o 1Q? f 192 a mi r 176 l 174 a L/ l Q B j E Inventors Z58 ErnestWSzczceg F. 5 43 Daniel T/Vc'zl/aerfiannczble g George KEZchardsonArZhurEHubbard Feb. 20, 1951 E. w. STACEY ETAL ARMED MOUNT FOR AIRCRAFTFiled Nov. 1, 1946 15 Sheets-Sheet 6 Em estWS'fa'cey bZe Ar'Z/ZUP'ZEHubbard B thez' rAztorney Feb. 20, 1951 E. w. STACEY ETAL ARMED MOUNTFOR AIRCRAFT Filed NOV. 1, 1946 15 Sheets-Sheet 7 Arthuriff Hubba rdFeb. 20, 1951 E. w. STACEY ETAL ARMED MOUNT FOR AIRCRAFT Filed Nov. 1,i946 l5 Sheets-Sheet 8 e UJ Swam mmnrMw fl au mwxwm 7 dfi Feb. 20, 1951E. w. STACEY ETAL 2,542,217

ARMED MOUNT FOR AIRCRAFT Filed Nov. 1, 1946 15 Sheets-Sheet 9 InvenfarsErnest WSzacey Danie! Walker Harzrzable George K. Richardson Art/1 urR.Hubbard B f/zez'rA zzorney E. W. STACEY ETAL ARMED MOUNT FOR AIRCRAFTFeb. 20, 1951 i5 Sheets-Sheet 10 Filed Nov. 1, 1946 Inventors ErnestWSzacey Daniel VVa'Z/rerHamzabZe George Kfficharason ArzhurlaHubbard BtheZrAttorrzey Feb. 20, 1951 E. w. STACEY ETAL ARMED MOUNT FOR AIRCRAFT15 Sheets-Sheet 11 Filed Nov. 1, 1946 2. 0 3 2 W s f mm Z15 f .n r 1 nWHM Em w m WEE lfl n I 2 I r aKm 9 4m WWI MG By zhezrAzzforrzey I a l 4' 7Feb. 20, 1951 E. w. STACEY EIAL 2,542,217

ARMED MOUNT FOR AIRCRAFT Filed Nov. 1, 1946 15 Sheets-Sheet l2 fnvemorsErnesz WSzacey Daniel LVaZlcerHannabZe Gearge K Ric/1a ra'son Arthur.71?- Hubbard 5 their Aorney Feb. 20, 1951 E. w. STACEY ETAL 2,542,217ARMED MOUNT FOR AIRCRAFT Filed NOV. 1, 1946 I5 Sheets-Sheet 13 InventorsDaniel l Valkerficznnable ArzhurEHab/Zvarci Feb. 20, 1951 E. w. srAc-EYETAL 2,542,217

ARMED momma" FOR AIRCRAFT Filed Nov. 1, 1946 15 Sheets-Sheet 14 E. W.STACEY ETAL ARMED MOUNT FOR AIRCRAFT Feb. 20, 1951 15 Sheets-Sheet 15Filed Nov. 1, 1946 nveniors .Ern esz WSzacey Daniel VVELZ/ceFHcmnQbZeGeorgeffEz'ch ards'an n ing drawings in which,

mount on lines V--V, VI-VI and 1 Figs. 1, and 6, respectively;

Patented Feb. 20, 1951 ARMED MOUNT FOR AIRCRAFT Ernest W. Stacey, DanielWalker Hannable, and Arthur R. Hubbard, Beverly, and George K.Richardson, Wenham, United Shoe Machinery Corporation, Flemington, N. Ja corporation of New Jersey Application November 1, 1946, Serial No.707,216

6 Claims.

This invention relates to ordnance and is illustrated as embodied in anarmed mount for use in carriers such, for example, as aircraft, it beingeffectively projected to a firing position outside the aircraft.

The turret is mounted for pivotal movement in elevation upon an azimuthring rotatable upon a support ring which has secured to it a pluralityof ball-bearing nuts threaded onto screws rotatable in the fuselage,rotatio of said screws by power-operated mechanism, causing the supportring, together with the azimuth ring and the turret, to be moved to andfrom its operative position, in which the turret is arranged in itsprojected firing position. The illustrative turret has fixedly mountedin it ammunition feeders and chargers for cannon secured to the turret,and hydraulically powered drives, controlled by grips manned by thegunner, for operating the turret in azimuth and elevatio to train saidcannon.

The various features of the invention including projecting andretracting means for moving the mount to and from a firing positionoutside the turret, improved driving means for operating the turret andstop mechanism for limiting movement of said turret in elevation will beunderstood and appreciated from the following description read iconnection with the accompany- Figs. 1 and 2 are left side and rearviews, re-

spectively, of the armed mount and mechanism for moving said mount froma retracted position in a fuselage of an airplane to and from a.projected firing positio outside said fuselage;

Figs. 3 and 4 are elevations, partly broken away and partly in section,showing, upon an enlarged scale, portions of said mechanism for 1projecting and retracting the armed mount, as "viewed on lines III-III,IVIV,respectively' of j Fig. 1;

Figs. 5, 6 and ,7 are sections of the armed VIP-V I 0f Mass., assignorsto Fig. 8 is a plan view on line VIII-VIII of Fig. 7, showing mechanismfor moving an azimuth ring upon a support ring of the mount;

Fig. 9 is a schematicview of azimuth and elevation drives for theillustrative mount;

Fig. 10 shows in side elevation azimuth and elevation fluid drive pumps;

Figs. 11 and 12 are enlarged views showing in side elevation grips usedin training guns or cannon of a turret of the mount and also showingportions of drives between the grips and the azimuth and elevation fluiddrive pumps;

- Fig. 13 is a plan view of mechanism illustrated in Fig. 12;

Fig. 14 is a view showing portions of the azimuth drive of Fig. 12 whenthe grips have been displaced to move the turret in azimuth;

Figs. 15 and 16 are views in plan and elevation, respectively, partlybroken away, showing portions of the azimuth drive adjacent to theazimuth fluid drive pump;

Figs. 17 and 18 are views in plan and elevation, respectively, partlybroken away, showing portions of the elevation drive adjacent to theelevation fiuid drive pump;

Fig. 19 shows in side elevation portions =0f mechanism operated by theazimuth and elevation fluid drive pumps as viewed on line XIXX[X of Fig.6;

Fig. 20 is a view on line XXXX of Fig. 6 showing portions of elevationlimit stop mechanism, and

Fig. 21 is a view showing portions of the mechanism illustrated in Fig.20 when the limit stop mechanism has taken over control of the movementof the turret in elevation.

The illustrative armed mount, which comprises a turret 40, will bedescribed as installed in the upper part of a fuselage of an airplane,

portions of which are shown at 42 (Figs. 1 and 2), said turret beingsupported for rotation in elevation, by mechanism hereinafter described,upon an azimuth ring 43 (Figs. 1, 2, 5, 6,7 and 8) rotatable in azimuthupon roller bearings 44 (Figs. 6 and 7) of a support ring 46. In orderto move the turret 46 from an inoperative or returret.

lngs (not shown) in housings 55 (Figs 1 and 2), 60 (Fig. *1), secured byscrews 62 to the fuselage 42 and the lower ends of the screws 56 aremounted in thrust bearings 64 (Fig. 3) in housings 6i, 61a (Fig. 1)secured by screws 63 to the fuselage 42. The base nuts .48 such asherein illustrated are wellknown in the art and need not be furtherdescribed herein.

Power for moving the turret 46 to and from its firing position issupplied by a reversible elec; tric motor 66 (Figs. 1, 2 and 4) a" shaft58' (Fig. 4) of which ha secured to ita gear 12 operatively connected toa gear 12 formed integral with a sleeve I4 mounted for rotation upon ashaft I6 (Figs. 2, 3 and 4) and restrained against lengthwise movementon the shaftby" a bearing bracket I8 (Figs. 2 and 4) secured to thefuselage 42. The shaft I6 is supported at its opposite ends in bearings86 (Fig. 3) in the fuselage 42 and has secured to its opposite ends,sprockets .82 (Figs. 1, 2 and 3) which are operatively connected bychains 84 to sprocketsst mounted at the inner ends of shafts 88 (Fig. 3)rotatably mounted in ball bearings 9|] in the housings BI.

The shaft I6- may be operated by mechanism,

which will be described presently, through a clutch 92 (Fig. 4) splinedfor rotation with said shaft. Secured to each of the shafts 8B is a worm94 (Fig. 3) which meshes with a worm gear 96fixed to the lower end ofone of the; two inner screws '56.

Mounted upon sprockets 98 (Figs. 1, 2 and 3) secured to the outer endso'fthe shafts 88 are chains 596 which are operatively connected tosprockets I62 (Fig. 1) fixed to corresponding shafts I64 in two of the.hous-; .in'gs. 6Ia,'the construction and arrangement of theabove-mentioned mechanism being such that, upon rotation of the shafts88, I04, the header screws 56, which are simiar toeach other, rotate atthe same speed to raise or lower the, support ring 46 parallel to itselfsaid screw.

' "The'clutchaI-IZcomprises a pair of friction disks I08, III] (Fig. 4)secured to a collar I I2 which is splined to the shaft I6; Engagingopposite sides of a circumferential groove of the collar 1 I2 are a pairof rolls H4 rotatably mounted upon bifurcations of a lever H6 (Figs. 2and 4) fulmrumed upon a pin H8 secured to the bracket I8.Counterclockwise movement of the lever I I6,

-. as-Viewed in Fig. 4, causes the friction disk I68 of the collar I12to be forced against the gear 12 with the result that the shaft I6 isrotated in response to movement of said gear. Clockwise movement ofthe'lever H6, as viewed in Fig, 4,

"causes the disk H9 of the collar to be forced against a stationaryplate I26 secured to the bracket 1'8 so as to retain the shaft againstro- 'tation when the'clutch is disengaged.

The lever H6, which is normally urged clock- ;wise, as viewed in Fig. 4,by a spring 524, opposite ends of which are attached to the lever and toa frame fixed to the fuselage 42, may be moved counterclockwise againsttheIaction of said spring,

to cause the turret 40 to be moved to and from its firing position,under the control of a crewman inside the fuselage or a gunner insidethe The gunner operates the lever M6 by through a rod I28, a roll N6 ofan offset bell-- crank lever I32, which is secured to a shaft I34trunnioned on the fuselage frame, upward against ithe action of thespring I24 and againstthe 9.0-

tion of a spring I35. In order to insure that the screws 56 shall notturn under the weight of the turret 46 and its azimuth and support rings43, 45, there are mounted upon the shafts 38, I04 friction clutches I36- (Fig. 3) which have to be overcome by the motor drive in moving theturret to its retracted position.

The turret 46 is hydraulically powered from within and has incorporatedin it, upon headers forming part of a frame I40 rigidly secured to andforming part of the turret 43, a pair of 37 mm. guns I42 (Figs. 1 and 5)to which ammunition is automatically supplied by a pair of feeders I44(Fig. 5) which are secured in fixed relation to initially chambered inthe guns by chargers I48 which. the gunner operates manually by cranksI50, i56a (Figs. 5 and 9) and are disclosed in application for UnitedStates Letters Patent Serial No. 659,053, filed April 2, 1946, nowPatent No. 2,529,822 in the name of Stacey et al. Openings I52 (Fig. 5)in the turret 40 through which barrels I54 (Figs. 1 and 5) of the gunsI42 project, are closed. by seal clips I56, the inside of the turretbeing protected against cold by insulation I58 (Fig. 5). The gunnerenters the turret 40 through a door I66 (Fig. 1) and sits on a stool I62(Fig. 5) in a compartment I64 of the turret positioned in front of thefeeders I44 and between the guns I42 which are provided with suitablesights (not shown) located outside front windows I66 (Fig. 1) of theturret. Hydraulic power mechanism of the turret is controlled by tationof the grips I58 about a vertical axis IIU (Figs. 9, 11 and 12) causes,through mechanism hereinafter described, movement of a valve rod I singa button (not shown) to energize a sole- H2 (Figs. 9,10, 15 and 16) tocontrol the operation of an'azimuth pump Il which actuates an azimuthhydraulic motor I16 (Figs. 5, 9, 19

and :20) for moving the turret 46 in azimuth.

Rotation of the grips I68 about a, horizontal axis I'IB (Figs. 5, 9, 11and 12) causes, through mechanism which will be described later,movement of a valve rod I86 (Figs. 9, 10, 1'7 and 18) to control theoperation of an elevation pump I82 which operates an elevation hydraulicmotor I84 (Figs. 9 and 19) for driving the turret 42 in elevation abouttrunnions I86 (Figs. 5, 6 and 7) of said turret. The azimuth andelevation pumps I14, I82, which are ofthe variable displacement type andare controlled by the valve rods I12, Iiiilwhich move a wobble plate(not shown), are powered by electric motors I83, I85 (Figs. 5 and 10),respectively.

The trunnions I86 are secured by a plurality of screws I88 (Fig. 6) toend. plates of the turret .40 reinforcedby theframe I40 of the turretand a collar I92 (Figs. 5, 6 and 7). The trunnions I86 pass throughregistering openings formed in the frame I40, said end plates and thecollar I92 of the turret, and are supported by ball bearings .194 "(Fig"6) mounted upon the azimuth ring 43.

As will be explained later, the left trunnion I86,

a s'yieWed from the rear, is bored to receive a shaft I96 (Figs. 6 and77) forming a portion of an azimuth drive extending outside the turret40 and comprising a sprocket or gear I98 (Figs. '7, 8 and 9.) which ismounted for rotation upon a bearing or pin 200 supportedby acarrier,.lever mechanism which will be described later. Ro-

tation of the sprocket I98 upon movement of the grips I68 about the axisI18 from neutral position shown in Fig. 9 causes, throughmechanismthereinafter described, the turret 48 to move- :in azimuth uponits axis 288 (Figs. 1 and 2) upon :the azimuth ring 43.

' Secured by bolts 2I8 (Figs. 6 and 7) to the azimuth ring 43 at itsopposite sides are arcuate frames 2I2 and supported by said frames aregear segments 2 I4 teeth of which mesh-with teeth of gears 2I6,respectively, fixed to the opposite ends of a shaft 2I8 (Figs. 6, 7,Qand 19) which is rotatably mounted in bearings of the turret frame andis driven in opposite directions by mechanism comprising the electricmotor I85 and the hydraulic motor I84 in response to clockwise andcounterclockwise displacement of the grips I88 from their neutralpositions shown in Fig. 9, about the axis I18. 2I4 are secured to thearcuate frames 2I2 by bolts 222 (Figs. 6 and '7) which pass throughelongated arcuate recesses 224 of the gear segments 2I4, clamp screws226 (Fig. 7) being provided to insure against lengthwise displacement ofthe gear segments from their initially adjusted positions.

The azimuth ring 43 is mounted upon the The gear segments rollerbearings 44 which are assembled in a circular cage 228 (Figs. 6 and '1)positioned upon the support ring 46, arcuate cover plates 298 (Figs. 1,2 and 6) and cylindrical skirts 232 being .provided to enclose turretoperating mechanism extending outside the turret. The azimuth ring .43is retained again t movement away from the support ring 46 by flanges223 (Figs. 6 and 7) of depending studs 225 bolted to the azimuth ring,said flanges underlying a plate 221 fastened by screws to the su portring 46. Rntatably mounted upon the studs 225 are rollers 23I which areconstantly in engagement with a cylindrical face 229 of the support ring46.

The mechanism for connecting the grips I 68 with the valve rod I12 ofthe azimuth pump I14 which operates the azimuth hydraulic motor I16 willnow be described. The grips I68 are secured to a shaft 234 (Figs. 11, 12and 13) which is fulcrumed for rotation in upstanding arms of ,a spool236 (Figs. 5, 9, 11,12 and 13) and is mounted for bodily rotation aboutthe axis I18 upon a cylindrical support 248 of the frame of the turret48.

'Movement of the s ool 236 in opposite directions upon the support 248is limited by the engagement of forward projections 233 (Figsll, 12 and13), of the spool with a stud 235 secured to the support. The spool 236has at its lower end a laterally extending arm 242 operatively connectedto a rod 244 which is connected, through an offset bell-crank lever 246journaled in the turret frame,

to a vertical rod 248 (Figs. 9 and 11). Pivotally "lever 268. receivinga roll 264. carried 'byfan' offset .bell-crank lever 268 journaled inthe .tur'ret theirneutral positions shown in Fig. 9 oil is bypassed inthe pump and when the grips are displaced'about' the axis in onedirection .or .the other, the flow of oil is delivered in one directionor the other through the pipes 269, the direction and the amount of theflow. of fluid in said pipes varying in accordancewith the displacementof the grips from their neutral positions about the axis and thedirection of 'such displacement- In order to insure that the grips I68when released by the gunner shall move back to their neutral positionsabout the axis I18, the lever 246 (Figs. 9, 11, 12, 13 and 14) hassecured to it a beam 218 constructed and arranged to be engaged by aspring-pressed plunger 212 which is slidingly supported in a housing ofthe turret frame and is constantly urged against said beam .by a spring214 (Figs. 12 and 14).

drivingrelation with a splined portion 218 (Figs. .9 and 19) of a shaft288 which has another splined portion 282 in driving relation with aninternally splined portion of a thimble 284 (Fig. 19) secured to ahollow shaft 286 mounted in bearings 288 supported in a housing of theturret frame. Secured to the shaft 288 is a circumferentially groovedcollar 298 which, as will be explained later, may be moved lengthwisewith the shaft by a shifter 292 to withdraw the splined portion 218 ofthe shaft out of driving relation'with the rotor 216 and into drivingrelation with a spiral gear 293 which, as will appear'later, isoperatively connected to mechanism manually operated by the crank I58.The crank I56 serves to operate the charger of the left gun and may bethrown out of driving relation with the charger and into operativerelation with the (Figs. 6, 9 and 19) meshing with a bevel gear 291secured to the shaft I96 (Figs. 6 and 7) which passes through the lefttrunnion I86 and is operatively connected by gears 298, 388 (Figs. 6, '1and 9) and a worm 392, all mounted for rotation in the azimuth ring 43,to a worm gear 394 (Figs. '1 and 9) secured to the upper end of thevertical shaft 284 which is also rotatably mounted in the azimuth ringand has secured to its lower end a gear 388 (Figs. 7, 8 and 9) indriving engagement with a gear 3I8 secured to an extension sleeve of thesprocket I98, which as above described, is pivotally mounted upon thebearing or pin 288 supported by the carrier or lever 282.

pose of which will appear presently. The rollers paranoia 1'1 .342 andflanges :of the support ring upon which the rollers are mounted serve as:a rack forming part of the support ringand may be so defined. Since,:as :above explainedxthe turret 48: has to operate in temperatures whichfluctuate considerably, and is mounted upon the :fuselag-e 42, which isrelatively :fiexible, considerable 'diificu'ltywou1d be encountered'werethe azimuth ring '43 *driven through a gear mounted for rotationabout a fixed center in said ring. Accordingly, in the illustrativeconstruction, the sprocket I198 is swingable together with its carrieror bracket 202 about the axis of the shaft 204, teeth of the sprocketbeing held in meshing engagement with the rollers 3J2 "on the pins -3I'4:by a :cam 320 which :is pivotally supported upon the pin 2-80 and hasan arouate groove 322 which travels along the rollers 318 :as the:azimuth ring 43 rotates. The sprocket 198 may be "defined as beingmounted for swinging movement in the general plane of the rack 286.

The 'mechanism for operating the elevation pump I82 (Figs. 5,, I9, 10.,1'7 and 18) in response to rotation of the grips I38 about the axis 118will now be described. Clamped by a screw 324 (Figs. 5, 11, 12 and 13)to the grip shaft 234 is a sleeve 328 (Figs. 9 and 13) having aforwardly projecting arm 328 operatively connected through a rod 33.8with an arm 332 .secured to one 'end of a shaft 334 rotatably mounted inthe turret frame. In order to limit rotation of the sleeve 326 and,accordingly, rotation of the grips 468 in opposite directions about theaxis I18, the .arm 3281s provided with abutments 3331(Figs. 11

and 12) constructed and arranged to engage a stud 33.5 secured to thespool 236. Secured to the opposite end of the shaft 334 :is an arm 336carrying a pin 338 (Figs. 11 and 13) extending into slots 348' formed ina bifurcation of a lever 342 fulcrumed on a stud 344 secured to the turret frame.

Secured to the "forward end of the lever 342 is a pin 346 which extendsthrough elongated slots formed in bifurcations of a lever 348 secured toone end of a shaft 358 rotatably mounted in the turret frame and havingsecured to its opposite end a lever 352 (Figs. 9 and 11) operativelyconnected by a rod 354, a bell-crank lever 35%, and a rod 358 to an arm360 (Figs. 9, 17 and 18) secured to a lower end of a shaft 362 rotatablymounted in the turret frame. Secured to the upper end of the shaft 362is a lever 364, one end of which is operatively connected through a rod365 and a multi-armed lever 368 mounted for rotation in the turretframe, with the valve rod I88 for controlling the amount and directionof flow of fluid in pipes 31!) (Figs. 9 and connecting the elevationpump I82. and the eleva- 'tion hydraulic motor I84.

.The portion of the drive between the elevation hydraulic motor 384(Figs. 9 and 19) and gears 2I6 (Figs. 6, 7 and 9), rotation of whichalong the gear segments 2 I4 causes the turret to swing in elevation, issimilar to corresponding parts of .theazimuth drive and comprises ashaft 312 (Figs. 9 and 19) having a splined portion 314 in drivingrelation with a rotor 31E- of the elevation hydraulic motor I84. Theshaft 312 is normally rotatably supported upon splines of a gear 373,rotatable in bearings 31'! (Fig. 19) mounted in a drive assembly housingsecured to the turret frame, and is splined to drive an internallyfluted .thimble 319 screwed to a hollow shaft 318 which .is rotatablysupported in bearings 388 in said ,assembly housing. The shaft 312 maybe moved to the left into the hollow shaft 318 froniiits position shownin Fig. 19 upon swinging clo'ckwise a shifter 382 :having pins engagingin the opposite sides of a circumferential groove in a collar 384secured to the shaft 312, thus with drawing the spline 314 from itsdriving engagement with the rotor 315 and securing it for :rotationwiththe gear 333 which, as will be .here inafter described, is manuallyoperated by the crank [563a (Figs. Band '9.) mounted in the gunnerscompartment. As above explained the crank 5801, is also used to chargeth'e'right .142 but by use of a clutch (not shown) may be :operativelyconnected through mechanism here-' inafter described with the gear 313for the purpose of -manually moving the turret in elevation.

{Formed upon the shaft 338 is a worm 386 in meshing arrangement with aworm gear 388 secured to one end of a shaft see which is rotatabl y.mounted in the drive housing of the turret "frame and has secured toits other end agear 398 in driving relation with a large gear 392 (Figs.6, 9,119 and 20.) secured to the shaft 2 I8. I

The circumferentially grooved collars 298, 384 (Figs. 9 and 19.) throughwhich the azimuth and elevation shafts 238, 312 are moved lengthwiseinto and out of operativeengagement with the rotors 213, 3'55 of theazimuth and elevation motors I13, I84, respectively, are operated by theshifters .232, 382 mounted upon shafts 394, 393

.rotatably mounted in the drive housing secured to the turret frame.

Pivotally secured through couplings 398, 39811. to levers 488 fixed tothe opposite ends of the shafts 394, 336 are flexible cables 382, 484(Fig.

19) leading to the turret compartment I84 and to a compartment in thefuselage 42 respectively, the arrangement being such that the shafts288, 31'2 may be selectively slid in one direction or the other by thegunner, or by a crewman located in a compartment of the fuselage, tocause the azimuth and elevation hydraulic drives, in event that they areoperative, to be effective or, in case the hydraulic drive should fail,to enable the gunner manually to swing the turret in azimuth andelevation through mechanism which will now be described. Meshing withthe spiral gear 293 is a spiral gear 48% (Figs. 9 and 19) secured to theouter end of a shaft 488 to the inner 'end of which a sprocket cm (Fig.9) is secured. Mounted in the frame of the turret near the left wall ofthe compartment I84 is a shaft 4I2 (Figs. 5 and 9) one end of which issecured through the clutch 294 to the crank I and the other end of whichhas secured to it a sprocket 444 (Fig. 9) connected by a chain 4It tothe sprocket M8. Through similar mechanism the spiral gear 376 isop-rativ-e1y connected to a spiral gear 4I8 (Figs. 9 and 19) mountedupon a shaft 428 rotatably mounted in the turret frame and having at itsinner end a sprocket 422 (Fig. 9) operatively connected through a chain424 to a sprocket 423 fixed to the outer end of a shaft 428 which ismounted for rotation in the turret frame and has secured to its innerend the crank I50a. which is provided with a clutch (not shown)corresponding with the clutch 2 34.

lhe armed turret 40 when in its projected firing position outside thefuselage 42 maybe rotated clockwise or counterclockwise in azimuththrough an unlimited number of degrees. Movement of the turret 43 inpositive elevation is limited when the guns 32 are disposed atapproximately to the general plane of its azimuth ring 43. Movement ofthe turret and.

accordingly, the guns in negative elevation is limited at differentdegrees in accordance with the position of the guns in azimuth, the gunsbeing depressed until their barrels I54 are in approximate engagementwith the body of the fuselage 42. It will be understood that when theguns I42 are trained broadside they can be depressed more than when theyare pointing somewhat forward and aft of the fuselage 42. With theforegoing in view, hereinafter described mechanism comprising a normallyfixed but initially adjustable stop 43!) (Figs. 6, 9 and 20), which isengaged by a roll 432, is provided to stop movement of the guns inpositive elevation just before they reach 90. A masking cam 434 isengaged by the roll 432 just before the turret 48 is moved in negativeelevation to a position in which the barrels I54 of the guns I42 arelikely to collide with the fuselage 42. Since the barrels I54 of theguns I42 can be moved in PQ itiv elevation to approximately 90, for allpositions in azimuth of the turret, the fixed stop 430 is used. Inorder, however, to insure that the field of fire of the guns I42 innegative elevation shall be as great as possible, it is necessary toprovide the masking can 434, which is movable in response to movement ofthe turret 48 in azimuth and is shaped to enable the barrels I54 of theguns I42 to move into close proximity with the fuselage 42 before theyare stopped.

The cam 434 is secured to one end of a shaft 436 which is rotatablymounted in a bearing of an azimuth drive housing 438 secured to theturret frame. In order to rotate the cam 434 degree for degree with theturret in azimuth, a Worm 440 (Figs. 9 and 19) on the hollow azimuthdrive shaft 286 has, in driving relation with it, a worm gear 442secured to a shaft 444 journaled in a bearing of the azimuth drivehousing 438 and having secured to its other end, a gear 446 which drivesthrough a gear 448, a shaft 458 and a gear 452, a gear 454 secured tothe cam shaft 436.

The large gear 392, which is secured to the elongated drive shaft 2I8,has formed in it a spiral cam groove 456 (Figs. 6, 9, 19 and 20) forreceiving a follower 458 on a block 468 (Figs. 6 and 20) mounted upon arod 462 (Figs. 6, 9 and 20) which together with a yoke 464 pinnedthereto'may be referred to as a slider. The cam groove 456 is sodesigned that the follower 458 moves equal distances radially of thegear 392 for equal degrees of rotation of said gear. The slider 462, 464may be described as being movable equal distances in a fixed path inaccordance with equal angular displacements of the turret in elevation.The rod 462 is mounted for reciprocation in alined bores 466 (Fig. 6) ofthe azimuth drive housing 438. In order to secure the yoke 464 againstrotation about the axis of the rod 462, the housing 438 has secured toit a stud 468 (Figs. 6 and 20) which fits in a channel 416-of the yoke.I The block 460 is initially secured in its proper position withrelation to the yoke 464 by a screw 412 (Fig. 6) threaded into the yokeand having its head fitting in a slot of the block 468, said screw beinglocked in its adjusted position by a lock nut 414.

Pivoted upon the yoke 464 is a bell-crank lever 416 (Figs. 6, 9, 20 and21) a horizontal arm of which-carries the cam roll or abutment 432 and avertical arm of which carries a pin 418 (Figs. 6, '20 and 21) fitting ina rectilinear channel 480 ofa T-shaped lever 428 which is pivoted toarms 484 secured to pins-486 respectively, fulcrumed in the azimuthdrive housing 438. One of the arms 484 is elongated and universallyconnected to a rod 488 operatively connected by an offset bell-cranklever 498 journaled in the azimuth drive housing 438 to the upper end ofa rod 492. Operatively connected to the lower end of the rod 492,through an offset bell-crank lever 494 and a rod 495 is the previouslymentioned lever 364 which forms part of the elevation pump controllingmechanism.

With the above-described construction it will be apparent that the cam434 rotates in timed relation with rotation of the turret 48 in azimuthand that the rod 462 secured to the yoke 464 moves along the bores 466of the azimuth drive housing equal distances for each degree of movementof the turret 40 in positive or negative elevation.

As above stated, the turret 48, regardless of its position in azimuth,can be moved in positive elevation until its guns I42 are disposed atapproximately 90 to the general plane of the azimuth ring 43, the fixedstop 43!] being engaged by the roll 432 for limiting, through mechanismabove described, movement of the turret and its guns in positiveelevation.

When the grips I68 have been displaced from their neutral positionsshown in Fig. 9 about the axis I18, the azimuth ring 43 rotates at afixed rate upon the support ring 46, the speed of rotation dependingupon the displacement about said axis. When the grips have beendisplaced clockwise, as viewed in said Fig. 9, from their neutralpositions about the axis I18, the turret 40 is moved at a fixed speed innegative elevation about the axis of the trunnions I86, the speed ofrotation depending upon the amount of displacement about such axis.

When the guns I42 have no motion in elevation, and are pointingbroadside the grips I68 being in a neutral position with respect to axisI18, the yoke 464 (Figs. 6, 9, 20 and 21) the lever 416 and its roll432, and the cam 434 will assume the positions illustrated in Fig. 20.Should the gunner, however, move the grips I68 clockwise as viewed inFig. 9 about the axis I18, the bellcrank lever 416 will rotate clockwiseas viewed in Fig. 20 with relation to the yoke 464 which will movedownward at a fixed rate. Before the guns have moved in negativeelevation to a position in which they are in danger of striking thefuselage, the roll 432 will engage the cam 434, causing the lever 416 tomove to its neutral position on the yoke 464, the pin 418 moving theT-shaped lever 482 to the right as viewed in Fig. 20, causing, throughmechanism above described, the elevation valve rod I80 to be so actuatedas to stop the flow of oil to the elevation hydraulic motor I16 and alsomoving the hand grips back to neutral position about the axis I18.

Assuming that the gunner should then move the grips I68 clockwise, asviewed in Fig. 9, about the axis I10, the guns if not raised inelevation would strike the fuselage. In order to guard against this, thecam 434, which is patterned to the fuselage and rotates in timedrelation with rotation of the turret in azimuth, has a plurality of highportions 496 one of which engages the roll 432 before there can be anycollision of the guns with the fuselage, causing the bell-crank lever416 to be moved counterclockwise to its position shown in Fig. 21, withthe result that the turret and its guns instead of stopping are furthermodified by moving them in positive elevation to avoid collision withsaid fuselage.

